AP BIOLOGY

Detailed explanation-1: -Answer and Explanation: The correct answer is C. ATP provides energy coupling between exergonic and endergonic reactions In order to provide the energy required to power endergonic reactions (reactions that need energy input), cells will couple the energy released from exergonic reactions to endergonic once.

Detailed explanation-2: -ATP synthesis is an endergonic reaction because to form a high energy bond, energy is required.

Detailed explanation-3: -When a phosphate group is broken off the tail of an ATP molecule (by hydrolysis) the molecule becomes ADP (adenosine diphosphate). That hydrolysis is an exergonic reaction and it yields energy.

Detailed explanation-4: -ATP transfers a phosphate group to the reacting molecule of the endergonic reaction. The energy from the phosphate group drives the endergonic process. This way, ATP transfers energy from an exergonic to an endergonic reaction.

Detailed explanation-5: -The hydrolysis of ATP into ADP and inorganic phosphate is an exergonic reaction because there is a positive change in free energy between products and reactants.